Brian Sutton
NASM-CPT, CES, PES, NASM Master Instructor
Understanding Tempo Notation
Tempo is typically written as a four-digit code: eccentric lowering phase (pause at bottom) concentric lifting phase (pause at top).
For example, a 3-1-2-0 squat means:
- 3 seconds lowering.
- 1 second pause at the bottom.
- 2 seconds to stand up.
- No pause at the top.
The notation makes the prescription precise and removes the ambiguity of “slow and controlled.”
The Eccentric Phase: The Most Underloaded Component
The eccentric (lowering) phase of any movement is where the greatest force is produced and where the most significant hypertrophic stimulus occurs. Muscle tissue is stronger eccentrically than concentrically—it can handle approximately 20 to 40% more load during lengthening than during shortening.
Yet most clients rush the eccentric, robbing themselves of the most productive portion of every rep. Lengthening the eccentric phase to 3 to 5 seconds has several documented effects:
- Greater mechanical tension on muscle fibers (the primary driver of hypertrophy).
- Increased muscle damage and subsequent remodeling.
- Improved connective tissue loading (particularly tendon and fascia).
For clients who have plateaued on conventional tempo, controlled eccentrics alone often restart progression.
The Isometric Pause
An intentional pause at the end of the eccentric (bottom of a squat, top of a pull, bottom of a push-up) eliminates the stretch-shortening cycle that allows the body to "bounce" out of the position using stored elastic energy. Removing the elastic rebound forces the concentric to be initiated from a dead stop.
This increases the neuromuscular demand and motor unit recruitment required to complete the movement. Paused squats, paused deadlifts, and paused bench presses are staples in strength-focused programming for exactly this reason.
The Concentric Phase: Speed Variation for Different Adaptations
The concentric phase can be manipulated two ways for different outcomes:
Slow concentric (2 to 4 seconds):
- Increases time under tension and metabolic stress.
- Particularly effective for hypertrophy-focused training.
- Extends the window of muscle fiber recruitment.
- Drives greater metabolic fatigue.
Fast/explosive concentric:
- Targets rate of force development (RFD)—the speed at which the neuromuscular system can produce force.
- This is the power adaptation.
- Athletes and clients who need to generate force quickly benefit from maximal-speed concentric training, including plyometrics.
Applying Tempo to Common Exercises
Practical Tempo Prescriptions for Specific Goals
Hypertrophy emphasis:
- 3-1-2-0 squat.
- 4-0-2-0 dumbbell press.
- 3-1-2-0 Romanian deadlift.
The extended eccentric and moderate concentric maximize time under tension.
Strength emphasis:
- 2-1-X-0 (X = maximal speed concentric).
- Heavier load with controlled—but not excessively slow—eccentrics and explosive concentric intent.
Plateau breaking:
- 5-0-1-0 (5-second eccentric, rapid concentric).
- 3-3-1-0 (3-second pause at bottom).
Applied to stalled movements, the novel stimulus often reinitiates adaptation after weeks of stagnation.
Corrective/stabilization focus:
- 3-3-3-0.
- Extended eccentric, extended pause, slow concentric. Maximizes time in challenging joint positions to improve stability and proprioception.
Programming Tempo Systematically
Tempo variation is most effective as a planned programming variable—not a random session-to-session change. Build tempo into the program the same way you prescribe sets, reps, and load.
A simple block structure:
- Weeks 1 to 4: Standard tempo (2-0-2-0) establishing baseline performance.
- Weeks 5 to 8: Extended eccentric tempo (4-0-2-0) at reduced load.
- Weeks 9 to 12: Explosive concentric (2-1-X-0) targeting rate of force development.
This three-phase structure targets all major adaptations within a single training block.
Programming Tempo with Purpose
Tempo is a free variable—it requires no additional equipment but can significantly change the training stimulus. For clients who have been training on autopilot, introducing deliberate tempo prescription often produces some of the fastest and most noticeable adaptation responses.
Make tempo a programmed variable, not an afterthought. The National Academy of Sports Medicine (NASM) Performance Enhancement Specialization (PES) and the Optimum Performance Training ™(OPT™) Model provide the periodization framework for integrating tempo systematically across training blocks.
Frequently Asked Questions For Tempo Training
What is tempo training in the gym?
Tempo training involves deliberately controlling the speed of each phase of a lift—the lowering (eccentric), pause, and lifting (concentric) phases—to target specific adaptations like hypertrophy, strength, or power. It's typically expressed as a four-digit code (e.g., 3-1-2-0).
Does slowing down reps build more muscle?
Extended eccentric tempo (3 to 5 seconds lowering) increases mechanical tension and time under tension, which are primary hypertrophy drivers. Research supports that controlled eccentrics produce greater hypertrophic stimulus than fast, uncontrolled reps at the same load. However, very slow tempos (super-slow training) may actually reduce hypertrophy by limiting loads that can be used.
How does tempo training break plateaus?
Tempo manipulation provides a novel neuromuscular stimulus without changing exercises or adding weight—introducing extended eccentrics, isometric pauses, or explosive concentric phases to movements a client has adapted to restarts adaptation by changing the mechanical and metabolic demands.
What tempo is best for beginners?
A moderate tempo of 2-0-2-0 (2 seconds down, no pause, 2 seconds up) is appropriate for beginners—it promotes movement quality and control without the complexity of advanced tempo prescription. As clients develop movement proficiency and hit first plateaus, introduce more deliberate tempo manipulation.
